U.S. patent application number 12/910074 was filed with the patent office on 2011-04-28 for method for converting network address.
This patent application is currently assigned to ELECTRONICS AND TELECOMMUNICATIONS RESEARCH INSTITUTE. Invention is credited to Hyoung Jun Kim, Jung Soo Park.
Application Number | 20110096782 12/910074 |
Document ID | / |
Family ID | 43898399 |
Filed Date | 2011-04-28 |
United States Patent
Application |
20110096782 |
Kind Code |
A1 |
Park; Jung Soo ; et
al. |
April 28, 2011 |
METHOD FOR CONVERTING NETWORK ADDRESS
Abstract
In a network environment in which an endpoint identifier and a
routing locator are separated from each other, a first router
receives a data packet including an endpoint identifier of a first
host and an endpoint identifier of a second host that is a
communication target of the first host from the first host managed
by the first router in order to convert a network address. A
message requesting external address prefix information of the
second host is transmitted to a second router managing the second
host. In addition, the external address prefix information is
received from the second router and a routing locator of the second
host is generated by converting internal address prefix information
of an endpoint identifier of the second host into the external
address prefix information of the second host in the data
packet.
Inventors: |
Park; Jung Soo; (Daejeon,
KR) ; Kim; Hyoung Jun; (Daejeon, KR) |
Assignee: |
ELECTRONICS AND TELECOMMUNICATIONS
RESEARCH INSTITUTE
Daejeon
KR
|
Family ID: |
43898399 |
Appl. No.: |
12/910074 |
Filed: |
October 22, 2010 |
Current U.S.
Class: |
370/392 |
Current CPC
Class: |
H04L 61/6059 20130101;
H04L 45/00 20130101; H04L 29/12915 20130101; H04L 61/2514 20130101;
H04L 45/74 20130101; H04L 29/12367 20130101 |
Class at
Publication: |
370/392 |
International
Class: |
H04L 12/24 20060101
H04L012/24 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 23, 2009 |
KR |
10-2009-0101341 |
Claims
1. A method for converting a network address in a first router of a
network environment where an end point identifier and a routing
locator are separated from each other, comprising: receiving a data
packet including an endpoint identifier of a first host and an
endpoint identifier of a second host that is a communication target
of the first host from the first host managed by the first router;
transmitting a message requesting external address prefix
information of the second host to a second router managing the
second host; receiving the external address prefix information from
the second router; and generating a routing locator of the second
host by converting internal address prefix information of the
endpoint identifier of the second host into the external address
prefix information of the second host in the data packet.
2. The method of claim 1, wherein the message includes the endpoint
identifier of the second host.
3. Them method of claim 1, wherein the internal address prefix
information is converted into the external address prefix
information in accordance with an address mapping algorithm.
4. The method of claim 1, wherein the generating includes
generating a routing locator of the first host by converting
internal address prefix information of the endpoint identifier of
the first host into external address prefix information of the
first host in the data packet.
5. The method of claim 4, wherein the first router stores mapping
information of the internal address prefix information of the
endpoint identifier of the first host and the external address
prefix information of the first host.
6. The method of claim 5, wherein the data packet transmitted to
the second router includes the routing locator of the first host
and the routing locator of the second host.
7. The method of claim 1, further comprising transmitting the data
packet to the second router in accordance with the routing locator
of the second host.
8. The method of claim 1, further comprising: receiving a reply
packet corresponding to the data packet from the second host; and
generating the endpoint identifier of the first host by converting
external address prefix information of the routing locator of the
first host into internal prefix information of the first host in
the reply packet.
9. The method of claim 1, comprising, when a third host moves to a
network managed by the first router: transmitting a message
requesting deletion of mapping information of the third host held
in a previous management router of the third host to the previous
management router; and receiving a reply message indicating that
the mapping information is deleted from the previous management
router.
10. The method of claim 9, wherein the mapping information includes
mapping information between internal address prefix information of
an endpoint identifier of the third host and external address
prefix information of the third host.
11. The method of claim 9, further comprising, when the third host
first communicates with the second host after receiving the reply
message, transmitting a data packet from the third host by forming
a tunnel with the second router.
12. The method of claim 11, wherein the data packet from the third
host includes an endpoint identifier of the third host, a routing
locator of the third host, the endpoint identifier of the second
host, and the routing locator of the second host.
13. A method for converting a network address in a first router
managing a first host in a network environment in which an endpoint
identifier and a routing locator are separated from each other,
comprising: receiving a message requesting an external address
prefix of the first host from a second router managing a second
host; transmitting the external address prefix of the first host to
the second router; receiving a data packet transmitted from the
second host from the second router; and transmitting the data
packet to the first host, wherein the data packet received from the
second host includes a routing locator of the first host generated
by converting an internal address prefix of an endpoint identifier
of the first host into the external address prefix of the first
host.
14. The method of claim 13, wherein the data packet transmitted
from the second host further includes a routing locator of the
second host.
15. The method of claim 13, wherein the data packet received from
the second host is generated by converting the internal address
prefix of the endpoint identifier of the first host into the
external address prefix of the first host in accordance with an
address mapping algorithm.
16. The method of claim 13, wherein the message includes the
endpoint identifier of the first host.
17. The method of claim 13, wherein the first router includes
mapping information of the internal address prefix of the endpoint
identifier of the first host and the external address prefix of the
first host.
18. The method of claim 13, further comprising: receiving a reply
packet corresponding to the data packet from the first host; and
generating a routing locator of the second host by converting an
internal address prefix of an endpoint identifier of the second
host into a external prefix of the second host in the reply
packet.
19. The method of claim 18, further comprising transmitting the
reply packet to the second router in accordance with the routing
locator of the second host.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to and the benefit of
Korean Patent Application No. 1 0-2009-01 01 341 filed in the
Korean Intellectual Property Office on Oct. 23, 2009, the entire
contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] (a) Field of the Invention
[0003] The present invention relates to a method for converting a
network address, and more particularly, to a method for converting
a network address in an Internet environment where an endpoint
identifier and a routing locator are separated from each other.
[0004] (b) Description of the Related Art
[0005] Recently, research into a fundamental structural problem of
the Internet based on the Internet protocol version 4 (IPv4) has
been in progress by organizations such as the Internet Engineering
Task Force (IETF) and the Internet Research Task Force (IRTF).
Herein, the structural problem includes routing scalability and
mobility of a global Internet scale.
[0006] Herein, the Internet performs routing while identifying a
node on a network by using an Internet protocol (IP) address. That
is, the IP address has both a function of an endpoint identifier
(hereinafter referred to as "EID") for identifying the node and a
function of a routing locator (referred to as "RLOC") for informing
of the location on the network. In order to solve the problem of
routing scalability at the time of using the Internet, the EID and
the RLOC are separated from each other so as to not be
simultaneously used, such as in a locator/identifier separation
protocol (LISP), an alternative logical topology (ALT), and a
protocol transit mapping service (APT). Likewise, the techniques
separating the EID and the RLOC from each other support efficient
multi-homing and traffic engineering by reducing an increase
tendency of a routing table of a backbone zone (default route free
zone) due to allocation of nonintegrated addresses and multi-homing
support. At this time, the EID is maintained while being associated
only with devices in a predetermined website without being
subordinated to a network provider, and the RLOC is an address
allocated in accordance with a network topology and is managed by
the network provider.
[0007] Meanwhile, a network address translation (NAT) is a device
for converting an address on a communication network, which is used
to convert a private IP address into a public IP address. In order
to solve a security problem by providing independence of an address
in the Internet protocol version 6 (IPv6) while maintaining the
advantages of the NAT, the use of an IPv6-based NAT66 (IPv6-to-IPv6
NAT) technology is increasing, which assures transparence between
endpoints while providing the address independence on the basis of
the IPv6. In the NAT66, an external address and an internal address
are mapped with each other one-to-one like a NAT that is generally
known. That is, the NAT66 does not need to maintain port mapping
information by not using a port mapping method but by using an
address mapping method, and does not need to newly calculate a
checksum value of a transport layer protocol. However, only mapping
information between an internal address prefix and an external
address prefix is maintained.
[0008] At the time of using the Internet, how the IPv4 and the IPv6
will be used by being applied to the EID and the RLOC that are used
to support the routing scalability and the mobility is not
described in detail.
[0009] Accordingly, a technology for applying the IPv6-based
network address converting technique to an Internet structure
combining the LISP and the ALT that is improved to support the
routing scalability and the mobility by separating the EID and the
RLOC from each other is required.
[0010] The above information disclosed in this Background section
is only for enhancement of understanding of the background of the
invention and therefore it may contain information that does not
form the prior art that is already known in this country to a
person of ordinary skill in the art.
SUMMARY OF THE INVENTION
[0011] The present invention has been made in an effort to provide
a method for converting a network address based on IPv6 for
applying an IPv6-based network address converting technique to an
Internet structure combining an LISP and an ALT that are improved
to support routing scalability and mobility.
[0012] An exemplary embodiment of the present invention provides a
method for converting a network address in a first router of a
network environment where an end point identifier and a routing
locator are separated from each other that includes:
[0013] receiving a data packet including an endpoint identifier of
a first host and an endpoint identifier of a second host that is a
communication target of the first host from the first host managed
by the first router; transmitting a message requesting external
address prefix information of the second host to a second router
managing the second host; receiving the external address prefix
information from the second router; and generating a routing
locator of the second host by converting internal address prefix
information of the endpoint identifier of the second host into the
external address prefix information of the second host in the data
packet.
[0014] Another embodiment of the present invention provides a
method for converting a network address in a first router managing
a first host in a network environment in which an endpoint
identifier and a routing locator are separated from each other that
includes:
[0015] receiving a message requesting an external address prefix of
the first host from a second router managing a second host;
transmitting an external address prefix of the first host to the
second router; receiving a data packet transmitted from the second
host from the second router; and transmitting the data packet to
the first host, wherein the data packet received from the second
host includes a routing locator of the first host generated by
converting an internal address prefix of an endpoint identifier of
the first host into the external address prefix of the first
host.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 is a diagram schematically showing a structure of a
network according to an embodiment of the present invention;
[0017] FIG. 2 is a diagram schematically showing an example of a
data packet type including an EID or RLOC address used in an
IPv6-based network according to an embodiment of the present
invention;
[0018] FIG. 3 is a diagram schematically showing a communication
procedure between hosts that do not move on a network according to
an embodiment of the present invention;
[0019] FIG. 4 is a diagram schematically showing a communication
procedure between hosts that move on a network according to an
embodiment of the present invention;
[0020] FIG. 5 is a diagram schematically showing a mapping
information updating procedure by movement of a counterpart host
between hosts previously performing communication on a network
according to an embodiment of the present invention;
[0021] FIG. 6 is a diagram schematically showing a prefix
information acquiring procedure by movement of a counterpart host
between hosts previously performing communication on a network
according to an embodiment of the present invention; and
[0022] FIG. 7 is a diagram schematically showing a communication
procedure by movement of a counterpart host between hosts
previously performing communication on a network according to an
embodiment of the present invention.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0023] In the following detailed description, only certain
exemplary embodiments of the present invention have been shown and
described, simply by way of illustration. As those skilled in the
art would realize, the described embodiments may be modified in
various different ways, all without departing from the spirit or
scope of the present invention. Accordingly, the drawings and
description are to be regarded as illustrative in nature and not
restrictive. Like reference numerals designate like elements
throughout the specification.
[0024] In the specification, unless explicitly described to the
contrary, the word "comprise" and variations such as "comprises" or
"comprising" will be understood to imply the inclusion of stated
elements but not the exclusion of any other elements.
[0025] FIG. 1 is a diagram schematically showing a structure of a
network according to an embodiment of the present invention.
[0026] As shown in FIG. 1, the network according to the embodiment
of the present invention includes ingress tunnel routers (ITR) 100a
to 100c, ALT routers 200a to 200e, and egress tunnel routers (ETR)
300a to 300c in order to apply an IPv6-based network address
converting technique in an Internet environment combining a
locator/identifier separation protocol (LISP) and an alternative
logical topology (ALT).
[0027] Modules 110a to 110c having a function of the IPv6-based
NAT66 (IPv6-to-IPv6 NAT) are mounted on each of the routers (ITR)
100a to 100c, and communication is performed by separating the
endpoint identifier (hereinafter referred to as "EID") and the
routing locator (hereinafter referred to as "RLOC") from each other
in accordance with the function of each of the NAT66 modules 110a
to 110c. That is, the routers (ITR) 100a to 100c maintain mapping
of an internal address prefix and an external address prefix of
each of hosts 111, 121, and 131 in networks 11 to 13 managed by the
routers 100a to 100c. In addition, the routers (ITR) 100a to 100c
maintain mapping of an internal address prefix and an external
address prefix of hosts 211, 221, and 231 in networks 21 to 23 that
are not managed by the routers 100a to 100c. Herein, the EID
includes the internal address prefix acquired from the router and
information of the corresponding host in a network as an IPv6
address block that is internally used in the network, and is
transmitted by being included in a partial region of a packet. The
EID is allocated once through a router at a first location and is
uniquely maintained. The RLOC as an IPv6 address block that is
externally used in the network includes an external address prefix
and the corresponding router (ITR) information, and is transmitted
by being included in the partial region of the packet.
[0028] The routers (ALT routers) 200a to 200e are hierarchically
configured. The routers (ALT routers) 200a to 200c hierarchically
integrate and maintain an external address prefix for routing in
order to rapidly detect the address prefix mapping information
maintained by the routers (ITR) 100a to 100c and the routers (ETR)
300a to 300c.
[0029] Modules 310a to 310c having a function of the IPv6-based
NAT66 are mounted on the routers (ETR) 300a to 300c, and perform
communication by separating the EID and the RLOC from each other in
accordance with the function of each of the NAT66 modules 310a to
310c. That is, the routers
[0030] (ETR) 300a to 300c maintain mapping of an internal address
prefix and an external address prefix of each of the hosts 211,
221, and 231 in the networks 21 to 23 managed by the routers (ETR)
300a to 300c in order to support the function of the NAT66 modules
310a to 310c. In addition, the routers (ETR) 300a to 300c maintain
mapping of an internal address prefix and an external address
prefix of the hosts 111, 121, and 131 in the networks 11 to 13 that
are not managed by the routers (ETR) 300a to 300c.
[0031] FIG. 2 is a diagram schematically showing an example of a
data packet type including an EID or RLOC address used in an
IPv6-based network according to an embodiment of the present
invention.
[0032] Referring to FIG. 2, the IPv6 address 400 used in the
IPv6-based network according to the embodiment of the present
invention is formed by 128 bits, and 64 lower bits of the 128 bits
maintain host information as a data region 430 as it is and 64
upper bits are divided into a prefix region 410 and a checksum
region 420. At this time, the internal address prefix or the
external address prefix is included in the prefix region 410. When
the address is converted between an inner part and an outer part,
the checksum region 420 includes a value that is compensated so as
to not change a checksum value.
[0033] FIG. 3 is a diagram schematically showing a communication
procedure between hosts that do not move on a network according to
an embodiment of the present invention.
[0034] In FIG. 3, assuming that the host 111 managed by the router
(ITR) 100a and the host 211 managed by the router (ETR) 300a
according to the embodiment of the present invention do not move on
the network, a communication procedure between the host 111 and the
host 211 will be described.
[0035] Referring to FIGS. 1 and 3, the host 111 according to the
embodiment of the present invention first transmits a data packet
to the router (ITR) 100a in order to transmit the data packet to
the host 211 (S200). At this time, the EID of the host 111 is a
sending source address for sending the data packet and the EID of
the host 211 is a destination address for receiving the data
packet.
[0036] When the router (ITR) 100a does not have information on the
RLOC corresponding to the EID of the host 211 which is the
destination address, the router (ITR) 100a cannot know which router
has the information on the RLOC of the host 211, such that the
router (ITR) 100a transmits a map request message to the router
(ALT router) 200a closest thereto. The map request message is
transmitted up to the router (ALT router) 200b closest to the
router (ETR) 300a through adjacent routers that are hierarchically
maintained in the router (ALT router) 200a. The router (ALT router)
200b lastly transmits the map request message to the router (ETR)
300a (S201). At this time, content for requesting information on
the external address prefix mapped with the internal address prefix
for forming the RLOC of the host 211 is included in the map request
message, and in addition, the EID of the host 211 is also included
in the map request message for the router (ETR) 300a to find the
information on the external address prefix of the host 211.
[0037] The router (ETR) 300a generates a map reply message
including information on the external address prefix mapped with
the internal address prefix of the host 211, and transmits the
generated map reply message to the router (ITR) 100a (S202).
[0038] When the information on the external address prefix of the
host 211 is received, the NAT66 module 110a of the router (ITR)
100a determines the RLOC of the host 211 by converting the
information on the internal address prefix of the EID of the host
211 into the information on the external address prefix in
accordance with an address mapping algorithm, and sets the RLOC as
the destination address. In addition, the NAT66 module 110a of the
router (ITR) 100a determines the RLOC of the host 111 by converting
the already known information on the internal address prefix of the
EID of the host 111 into the information on the external address
prefix in accordance with the already known address mapping
algorithm, and sets the RLOC as the sending source address. The
NAT66 module 110a of the router (ITR) 100a first transmits the data
packet to the NAT66 module 310a of the router (ETR) 300a on the
basis of the RLOC of the host 211, which is the destination address
(S203). Herein, the router (ITR) 100a holds the information on the
external address prefix information for determining the RLOC of the
host 211 for a predetermined time.
[0039] The NAT66 module 310a of the router (ETR) 300a determines
the EID of the host 111 by converting the information on the
external address prefix of the RLOC of the host 111 into the
information on the internal address prefix in accordance with the
address mapping algorithm, and sets the EID as the sending source
address. The address mapping algorithm according to the embodiment
of the present invention can be implemented as all mapping
algorithms that maintain a one-to-one mapping rule. The NAT66
module 310a of the router (ETR) 300a determines the EID of the host
211 by converting the information on the external address prefix of
the RLOC of the host 211 into the information on the internal
address prefix in accordance with the address mapping algorithm,
and sets the EID as the destination source address. The NAT66
module 310a of the router (ETR) 300a transmits the data packet to
the host 211 in accordance with the internal address prefix
included in the EID of the host 211 (S204). At this time, since the
NAT66 module 310a of the router (ETR) 300a does not perform
communication in a state where the NAT66 module 310a previously
knows whether the host 211 is a mobile host or a fixed host, the
NAT66 module 310a checks an environment regarding whether or not
tunneling occurs before operating the function of the NAT66.
[0040] The host 211 transmits the data reply packet with respect to
the data packet to the NAT66 module 310a of the router (ETR) 300a
when there is a reply message with respect to the data packet
(S205). At this time, the EID of the host 211 is the sending source
address for sending the data reply packet and the EID of the host
111 is the destination address for receiving the data reply
packet.
[0041] The NAT66 module 310a of the router (ETR) 300a determines
the RLOC of the host 111 by converting the information on the
internal address prefix of the EID of the host 111 into the
information on the external address prefix in accordance with the
address mapping algorithm, and sets the RLOC as the destination
address. In addition, the NAT66 module 310a of the router (ETR)
300a determines the RLOC of the host 211 by converting the
information on the internal address prefix of the EID of the host
211 into the information on the external address prefix in
accordance with the address mapping algorithm, and sets the RLOC as
the sending source address. The NAT66 module 310a of the router
(ETR) 300a transmits the data reply packet to the NAT66 module 110a
of the router (ITR) 100a on the basis of the RLOC of the host 111,
which is the destination address (S206).
[0042] The NAT66 module 110a of the router (ITR) 100a determines
the EID of the host 211 by converting the information on the
external address prefix of the host 211 into the information on the
internal address prefix in accordance with the address mapping
algorithm, and sets the EID as the sending source address. In
addition, the NAT66 module 110a of the router (ITR) 100a determines
the EID of the host 111 by converting the information on the
external address prefix of the RLOC of the host 111 into the
information on the internal address prefix in accordance with the
address mapping algorithm, and sets the EID as the destination
address. The NAT66 module 110a of the router (ITR) 100a transmits
the data reply packet to the host 111 on the basis of the EID of
the host 111, which is the destination address (S207).
[0043] FIG. 4 is a diagram schematically showing a communication
procedure between hosts that move on a network according to an
embodiment of the present invention.
[0044] In FIG. 4, assuming that a new host (not shown) moves to the
network managed by the router (ITR) 100a according to the
embodiment of the present invention, a communication procedure
between the host 221 and the new host will be described.
[0045] Referring to FIGS. 1 and 4, the router (ITR) 100a according
to the embodiment of the present invention recognizes that the new
host moves and comes and when an internal address prefix of the new
host is not the internal address prefix managed by the router (ITR)
100a, the router (ITR) 100a transmits a map request message to the
router (ALT) 200a closest thereto in order to transmit a map
request message indicating that the new host moves and comes to the
router (ITR) (not shown) (hereinafter, referred to as "previously
managed router (ITR)") that previously managed the new host. The
router (ALT router) 200a transmits the map request message from the
hierarchically maintained adjacent routers, and transmits the map
request message to the previously managed router (ITR) through the
hierarchically maintained routers (S300). Herein, the map request
message indicates that the new host moves and comes to the router
(ITR) 100a, and includes a domain directing a command to delete
mapping information of the new host maintained in the previously
managed router (ITR). Herein, the mapping information is the
connection information between the internal address prefix
information of the EID and the external address prefix information
of the RLOC.
[0046] The previously managed router (ITR) determines a map reply
message including information indicating that the mapping
information of the new host is deleted, and transmits the
determined map reply message to the router (ITR) 100a (S301). That
is, the previously managed router (ITR) maintains updated
information in which the mapping information of the new host is
deleted.
[0047] After the new host moves on the network 10, the new host
first transmits the data packet to the router (ITR) 100a in order
to transmit the data packet to the host 221 managed by the router
(ETR) 300b (S302). At this time, the EID of the new host is the
sending source address for sending the data packet and the EID of
the host 221 is the destination address for receiving the data
packet.
[0048] The router (ITR) 100a recognizes that it does not have
information on the RLOC corresponding to the EID of the host 221,
which is the destination address. Since the router (ITR) 100a does
not know which router has the information on the RLOC of the host
221, the router (ITR) 100a transmits the map request message to the
router (ALT router) 200a closest thereto. That is, the map request
message is transmitted up to the router (ALT router) 200e closest
to the router (ETR) 300b through adjacent routers that are
hierarchically maintained in the router (ALT router) 200a. The
router (ALT router) 200b lastly transmits the map request message
to the router (ETR) 300b (S303). At this time, content for
requesting information on the external address prefix mapped with
the internal address prefix for forming the RLOC of the host 221 is
included in the map request message, and in addition, the EID of
the host 221 is also included in the map request message for the
router (ETR) 300b to find the information on the external address
prefix of the host 221.
[0049] The router (ETR) 300b generates a map reply message
including information on the external address prefix mapped with
the internal address prefix for forming the RLOC of the host 221,
and transmits the generated map reply message to the router (ITR)
100a (S304).
[0050] Since the router (ITR) 100a does not manage the internal
address prefix of the new host, the NAT66 module 110a does not
operate. That is, the internal address prefix information of the
EID of the new host is allocated to the router where the new host
is first positioned and the router (ITR) 100a does not thus manage
the internal address prefix information, such that the router (ITR)
100a does not operate the NAT66 module 110a. Therefore, a tunnel is
formed between the router (ITR) 100a and the router (ETR) 30b in
order to perform a function generated in accordance with an
Internet structure of the general LISP and ALT, and the data packet
is transmitted through the tunnel (S305). Herein, only the external
address prefix for forming the RLOC of the new host is acquired
through the tunnel formed between the router (ITR) 100a and the
router (ETR) 300b. At this time, in a tunneling method through the
tunnel, the RLOC of the new host acquired through the tunneling is
encapsulated and transmitted by being, as it is, included in the
EID of the new host without using the address mapping
algorithm.
[0051] The NAT66 module 310b of the router (ETR) 300b decapsulates
only a packet included in the data packet transmitted through the
tunnel, and transmits the decapsulated packet to the host 221 set
as the destination address (S306). At this time, the EID of the new
host is the sending source address for sending the data packet and
the EID of the host 221 is the destination address for receiving
the data packet.
[0052] The host 221 transmits the reply packet with respect to the
data packet to the NAT66 module 310b of the router (ETR) 300b when
there is a reply message with respect to the data packet (S307). At
this time, the EID of the host 221 is the sending source address
for sending the data reply packet and the EID of the new host is
the destination address for receiving the data reply packet.
[0053] The NAT66 module 310b of the router (ETR) 300b determines
the RLOC of the new host by converting the information on the
internal address prefix of the EID of the new host into the
information on the external address prefix in accordance with the
address mapping algorithm, and sets the RLOC as the destination
address. In addition, the NAT66 module 310b of the router (ETR)
300b determines the RLOC of the host 221 by converting the
information on the internal address prefix of the EID of the host
221 into the information on the external address prefix in
accordance with the address mapping algorithm, and sets the RLOC as
the sending source address. The NAT66 module 310b of the router
(ETR) 300b transmits the data reply packet to the NAT66 module 110a
of the router (ITR) 100a on the basis of the RLOC of the new host,
which is the destination address (S308).
[0054] The NAT66 module 110a of the router (ITR) 100a verifies
whether or not tunneling with the new host occurs, and when the
tunneling does not occur, determines the EID of the host 221 by
converting the information on the external address prefix of the
RLOC of the host 221 into the information on the internal address
prefix in accordance with the address mapping algorithm to set the
EID as the sending source address. In addition, the NAT66 module
110a of the router (ITR) 100a determines the EID of the host 111 by
converting the information on the external address prefix of the
RLOC of the new host into the information on the internal address
prefix in accordance with the address mapping algorithm to set the
EID as the destination address. The NAT66module 110a of the router
(ITR) 100a transmits the data reply packet to the new host on the
basis of the EID of the new host, which is the destination address
(S309).
[0055] Next, a communication procedure when a counterpart host
moves in a state where a communication procedure is performed once
in advance will be described in detail with reference to FIGS. 5 to
7.
[0056] FIG. 5 is a diagram schematically showing a mapping
information updating procedure by movement of a counterpart host
between hosts previously performing communication on a network
according to an embodiment of the present invention.
[0057] In FIG. 5, it is assumed that after the host 221 of the
router (ETR) 300b that manages the network 22 on the network
according to the embodiment of the present invention performs
communication with the host 111 of the router (ITR) 100a that
manages the network 11 in advance, the host 221 moves to the
network 21 at the time when the host 111 attempts communication
with the host 221 again.
[0058] Referring to FIGS. 1 and 5, since the host 221 according to
the embodiment of the present invention moves to the network 21
managed by the router (ETR) 300a, the host 221 notifies a
previously managed router (ETR) 300a (hereinafter, referred to as
"previously managed router (ETR) 300a) that it moves to the network
21 (S400).
[0059] The router (ETR) 300a recognizes that the host 221 moves and
comes, and transmits the map request message to the router (ALT
router) 200b closest thereto in order to transmit the map request
message to the previously managed router (ETR) 300b of the host
221. The router (ALT router) 200b transmits the map request message
from the hierarchically maintained adjacent routers, and transmits
the map request message to the previously managed router (ETR) 300b
through the hierarchically maintained routers (S410). Herein, the
map request message indicates that the host 221 moves and comes to
the router (ETR) 300a, and includes a domain directing a command to
delete mapping information of the host 221 maintained in the
previously managed router (ETR) 300b.
[0060] The previously managed router (ETR) 300b generates a map
reply including information indicating that the mapping information
of the host 221 is deleted, and transmits the generated map reply
message to the router (ETR) 300a (S420). That is, since the host
221 moves from the network 22 to the network 21, the previously
managed router (ETR) 300b newly updates and stores the mapping
information with movement of the host 221. Herein, the mapping
information includes external address prefix information with
respect to the host 221 that moves to the network 21.
[0061] FIG. 6 is a diagram schematically showing a prefix
information acquiring procedure by movement of a counterpart host
between hosts previously performing communication on a network
according to an embodiment of the present invention.
[0062] In FIG. 6, it is assumed that the host 221 according to the
embodiment of the present invention moves to the network 21 managed
by the router (ETR) 300a from the network 22 managed by the router
(ETR) 300b, and thereafter the host 221 receives the data packet
from the host 111.
[0063] Referring to FIGS. 1 and 6, the host 111 according to the
embodiment of the present invention transmits the data packet to
the router (ITR) 100a in order to transmit the data packet to the
host 221 (S500). At this time, the EID of the host 111 is the
sending source address for sending the data packet and the EID of
the host 221 is the destination address for receiving the data
packet.
[0064] Since the router (ITR) 100a still does not know that the
host 221 moves from the network 22 to the network 21, the router
(ITR) 100a transmits the map request message to the router (ALT
router) 200a closest thereto in order to transmit the map request
message to the previously managed router (ETR) 300b of the host
221. That is, the map request message is transmitted up to the
router (ALT router) 200e closest to the router (ETR) 300b through
adjacent routers that are hierarchically maintained in the router
(ALT router) 200a. The router (ALT router) 200b lastly transmits
the map request message to the router (ETR) 300b (S510). At this
time, content for requesting information on the external address
prefix mapped with the internal address prefix for forming the RLOC
of the host 221 is included in the map request message, and in
addition, the EID of the host 221 is also included in the map
request message for the router (ETR) 300b to find the information
on the external address prefix of the host 221.
[0065] The router (ETR) 300b generates a map reply message
including information on the external address prefix with respect
to the host 221 that moves to the network 21 managed by the router
(ETR) 300a and transmits the map reply message to the router (ITR)
100a because the host 221 moves from the network 22 to the network
21, such that the mapping information of the host 221 is updated in
accordance with the procedure shown in FIG. 5 (S520).
[0066] If the external address prefix information with respect to
the sending source address of the host 111 that transmits the data
packet is the same as that of the destination address of the host
221 while the host 221 moves to the network 11 managed by the
router (ITR) 100a, the data packet is directly transmitted to the
internal host 221 without determining the RLOC.
[0067] FIG. 7 is a diagram schematically showing a communication
procedure by movement of a counterpart host between hosts
previously performing communication on a network according to an
embodiment of the present invention.
[0068] In FIG. 7, it is assumed that the host 221 and the host 111
performed the communication on the network according to the
embodiment of the present invention in advance and the host 221
moves from the network 22 managed by the router (ETR) 300b to the
network 21 managed by the router (ETR) 300a, and thereafter the
host 221 performs the communication with the host 111 again.
[0069] Referring to FIGS. 1 and 7, the host 111 according to the
embodiment of the present invention first transmits the data packet
to the router (ITR) 100a in order to transmit the data packet to
the host 221 (hereinafter referred to as "mobile host 221") that
moves between networks (S600). At this time, the EID of the host
111 is the sending source address for sending the data packet and
the EID of the host 221 is the destination address for receiving
the data packet.
[0070] Since the NAT66 module 110a of the router (ITR) 100a already
has the information on the RLOC corresponding to the EID of the
mobile host 221 that is the destination address in accordance with
the procedure of FIG. 6, the NAT66 module 110a determines the RLOC
of the mobile host 221 by converting the information on the
internal address prefix of the mobile host 221 into the information
on the external address prefix in accordance with the address
mapping algorithm, and sets the RLOC as the destination address. In
addition, the NAT66 module 110a of the router (ITR) 100a determines
the RLOC of the host 111 by converting the information on the
internal address prefix of the EID of the host 111 into the
information on the external address prefix in accordance with the
already known address mapping algorithm, and sets the RLOC as the
sending source address. The NAT66 module 110a of the router (ITR)
100a first transmits the data packet to the NAT66 module 310a of
the router (ETR) 300a on the basis of the RLOC of the mobile host
221, which is the destination address (S610).
[0071] The NAT66 module 310a of the router (ETR) 300a determines
the EID by converting the information on the external address
prefix of the RLOC of the host 111 into the information on the
internal address prefix in accordance with the address mapping
algorithm, and sets the EID as the sending source address. In
addition, the NAT66 module 310a of the router (ETR) 300a determines
the EID of the host 221 by converting the information on the
external address prefix of the RLOC of the host 221 into the
information on the internal address prefix in accordance with the
address mapping algorithm, and sets the EID as the destination
address. The NAT66 module 310a of the router (ITR) 300a transmits
the data packet to the host 221 on the basis of the EID of the host
221, which is the destination address (S620).
[0072] The host 221 transmits the data reply packet with respect to
the data packet to the NAT66 module 310a of the router (ETR) 300a
when there is a reply message with respect to the data packet
(S630). At this time, the EID of the host 221 is the sending source
address for sending the data reply packet and the EID of the host
111 is the destination address for receiving the data reply
packet.
[0073] The NAT66 module 310a of the router (ETR) 300a determines
the RLOC of the host 111 by converting the information on the
internal address prefix of the EID of the host 111 into the
information on the external address prefix in accordance with the
address mapping algorithm, and sets the RLOC as the destination
address. In addition, the NAT66 module 310a of the router (ETR)
300a determines the RLOC of the host 221 by converting the
information on the internal address prefix of the EID of the host
211 into the information on the external address prefix in
accordance with the address mapping algorithm, and sets the EID as
the sending source address. The NAT66 module 310a of the router
(ETR) 300a transmits the data reply packet to the NAT66 module 110a
of the router (ITR) 100a on the basis of the RLOC of the host 111,
which is the destination address (S640).
[0074] The NAT66 module 110a of the router (ITR) 100a determines
the EID of the host 221 by converting the information on the
external address prefix of the RLOC of the host 221 into the
information on the internal address prefix in accordance with the
address mapping algorithm, and sets the EID as the sending source
address. In addition, the NAT66 module 110a of the router (ITR)
100a determines the EID of the host 111 by converting the
information on the external address prefix of the RLOC of the host
111 into the information on the internal address prefix in
accordance with the address mapping algorithm, and sets the EID as
the destination address. The NAT66 module 110a of the router (ITR)
100a transmits the data reply packet to the host 111 on the basis
of the EID of the host 111, which is the destination address
(S650).
[0075] As described above, according to an embodiment of the
present invention, as communication is performed by applying an
IPv6-based network address converting technique that maintains a
mapping relationship between internal and external address prefixes
of EID and RLOC in the network 10, which is improved to support
routing scalability and mobility, tunneling is not used between
hosts in a case where hosts do not move, thereby reducing a load in
the network. In addition, as only an address prefix is maintained
by a NAT66 module on each of routers (ITR) 100a to 100c and routers
(ETR) 300a to 300c for applying an IPv6-based network address
converting technique, data communication can be performed without
maintaining mapping information of all the addresses.
[0076] In addition, according to an embodiment of the present
invention, since tunneling for communication is not used by
applying an IPv6-based network address converting technique to an
Internet structure combining an LISP and an ALT that are improved
to support routing scalability, it is possible to reduce a load on
a network. In addition, according to an embodiment of the present
invention, only an IPv6 address prefix is maintained by mounting a
function of a NAT66 on an ingress tunnel router (ITR) and an egress
tunnel router (ETR) associated with the IPv6-based network address
converting technique, such that it is possible to prevent a problem
in mapping information of all host addresses.
[0077] The above-mentioned exemplary embodiments of the present
invention are not embodied only by an apparatus and method.
Alternatively, the above-mentioned exemplary embodiments may be
embodied by a program performing functions that correspond to the
configuration of the exemplary embodiments of the present
invention, or a recording medium on which the program is
recorded.
[0078] While this invention has been described in connection with
what is presently considered to be practical exemplary embodiments,
it is to be understood that the invention is not limited to the
disclosed embodiments, but, on the contrary, is intended to cover
various modifications and equivalent arrangements included within
the spirit and scope of the appended claims.
* * * * *